以金銅核殼奈米粒子電催化二氧化碳還原反應

CO2 electrocatalytic reduction with gold-copper core-shell nanoparticles

王弘毅(Wang Hong-Yi)

指導教授 ： 陳家俊

國立臺灣師範大學/理學院/化學系/碩士(2018年)

https://doi.org/10.6345/THE.NTNU.DC.039.2018.B05

摘要

二氧化碳為造成地球上溫室效應的因素之一，因此如何降低二氧化碳的含量，便是人類近年來主要的研究課題。其中，使用電催化二氧化碳還原是其中一種重要的方法。由文獻已知使用銅金屬催化，相對於其他金屬，銅可以產生較多碳氫類產物，例如甲烷、乙烯、甲醇、乙醇等等。不過，目前的研究對於銅的催化效果尚未有定論。本篇試圖以金銅核殼奈米結構探討其催化效果，以及不同晶面對還原產物選擇性的影響。其中晶型分別為含有(111)晶面的立方體與含有(111)晶面的八面體，並由TEM、SEM、XRD、UV鑑定其結構。而還原產物以GC-TCD和GC-FID作分析，並以各產物的法拉第電流效率值來判定產物的選擇性。由實驗分析，純銅奈米立方體的還原產物主要為乙烯，純銅奈米八面體的還原產物主要為甲烷，金銅核殼奈米立方體在不同電壓下主要產物不盡相同，但是可以提高乙醇的電流效率，推斷金的加入可以降低部分反應機構的活化能，使反應機構中需要傳遞較多電子的醇類得以容易產生。

關鍵字

二氧化碳還原 ； 電化學還原 ； 電催化還原 ； 銅奈米粒子 ； 金銅核殼奈米粒子

並列摘要

Carbon dioxide is one of the factor of global warming; therefore, it is an important issue for human being that how to reduce the capacity of carbon dioxide. One of them is catalyze carbon dioxide reduction used electricity. According to literature, using copper-like catalysts could produce more hydrocarbon than other metal catalysts. For instance, methane, ethylene, methanol and ethanol, etc. However, there are no accurate conclusion on efficiency of copper-like catalysts so far. We try to explore about the efficiency of gold-copper core-shell nanoparticle, and discuss how different crystal plane could influence the selectivity of product. We synthesis cubes structure which include (100) crystal plane and octahedral structure which include (111) crystal plane. First, we use TEM, SEM, XRD AND UV-Vis to characterize the structure. Second, we use GC-TCD and GC-FID to analysis the product after reduction. Third, we calculate the Faradic efficiency of every reduction product to judge the selectivity. By experiments, major reduction product of copper nano-cubes is ethylene, and copper nano-octahedral is methane. However, major reduction product of gold-copper core-shell nano-cubes is not identical at different voltage, yet it could increase the Faradic efficiency of ethanol. We assume that adding gold element could decrease the activation energy of a part of elementary reaction step, causing that alcohols which include more electron transfer could produce more easily.

並列關鍵字

Carbon dioxide reduction ； Electroreduction ； Electrocatalytic reduction ； Copper nanoparticles ； Gold-copper core-shell nanoparticles

參考文獻

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